This invention relates generally to golf equipment and more particularly concerns a golf shot range finder.
In selecting a club for any given golf shot, the golfer visually estimates the distance from the golf ball to the target golf hole, identifies the particular club personally suited to the golfer for that distance under base conditions and then adjusts from the base club to the actual club selected according to increments of wind, slope, elevation and the like. Without proper base club identification, it is impossible to consistently achieve proper actual club selection.
U.S. Pat. No. 3,409,987 teaches a range finder which correlates the perceived height of a pin in the target golf hole to the yardage of the golf shot by use of a transparent window mathematically calibrated to a 7xe2x80x2-6xe2x80x3 high flag stick. The golfer must adjust for courses having flag sticks which are not 7xe2x80x2-6xe2x80x3 high by changing the distance at which the window is held from the golfer""s eye when the yardage is determined. This introduces further opportunity for error in every use because the golfer may not remember variation used or may not be consistent in positioning the range finder. In addition to the possibility of actual error, this variation leaves a question of confidence in the club selected and lack of confidence in the shot is a major cause of poor shots. Furthermore, the markings on the window, those intended and those resulting from scratches and dirt, confuse and obscure the registration of the pin and therefore the accuracy of the device. The ""987 patent also teaches the use of removable adhesive dots or strips to directly correlate the perceived yardage to the golfer""s base club selection. This is generally inadequate because, after a modest number of repositionings of the discs or strips, they will no longer satisfactorily adhere to the card. Furthermore, the adhesive of the discs or strips rapidly deteriorates in contact with rain or perspiration and they quickly become useless. From round to round, and even in the course of a round of golf, the timing and strength of the golfer may change, making it desirable to adjust the base club selections accordingly. An on-course change of the adhesive discs or strips is not practical under the best of conditions, it being increasingly likely with each change that the adhesive quality will be lost while on the course.
It is, therefore, an object of this invention to provide a range finder which is usable by a golfer standing at a golf ball to reasonably accurately nomographically determine the yardage from the golf ball to a target golf hole. Another object of this invention is to provide a range finder which nomographically correlates the distance between a golf ball and a target golf hole to the known height of a pin placed in the target golf hole. Still another object of this invention is to provide a range finder having a nomographically defined opening so as to avoid errors or confusion caused by markings or dirt in the in registration area of the range finder. A further object of this invention is to provide a range finder which can be used to nomographically correlate the yardage of a golf shot to either of two different golf pin heights. Yet another object of this invention is to provide a range finder which directly nomographically converts the perceived height of a pin placed in a target golf hole into a club selection. It is also an object of this invention to provide a range finder which permits the golfer to convert yardage indicia into indicia of the golfer""s personal club selections for various distances under base conditions.
In accordance with the invention, a device is provided for assisting a golfer to determine the yardage from a golf ball to a target golf hole and thus to select the proper base club for the golf shot. A flat card has an aperture with elongated top and bottom edges. The top edge is spaced from the bottom edge at parallel intervals taken across the edges by distances decreasing in length from one end of the aperture to the other. The front face of the card has a first plurality of the parallel intervals marked along the edges of the aperture and the back face of the card has a second plurality of the parallel intervals marked along the edges of the aperture. The distances across the aperture at the marked intervals are nomographically coordinated to intervals of distance from the golf ball to the pin placed in the target golf hole. The distance from the golf ball to the pin is thus determinable by coincidental alignment of one of the marked intervals with the pin when the pin is visually registered in the aperture by the golfer. To accomplish this, the golfer stands at the golf ball with the card held at a reading distance of approximately two feet from the golfer""s eyes. When the pin is fully registered between the top and bottom edges of the aperture, the golfer merely reads the yardage displayed on the card for the aligned marked interval. Preferably, the pluralities of parallel intervals are equally spaced and have lengths nomographically corresponding to sequential ten yard increments of the distance from the golf ball to the pin. If registration occurs between marked intervals, the golfer can easily interpolate between the marked intervals on either side of the registered pin. The front and rear face markings each nomographically correspond to a different pin length, such as frequently used flag sticks 7xe2x80x2-6xe2x80x3 and 6xe2x80x2-6xe2x80x3, so as to accommodate a greater number of golf courses.
To facilitate reading the nomographically marked yardages, a plate is mounted in sliding juxtaposition on the front face of the card. Preferably, a narrow, elongated slot is provided through the card with a parallel groove in the front face of the card. A guide fixed on the plate engages with the groove and a bolt extends through a hole in the plate and the narrow, elongated slot to a nut threaded on its end. The bolt and the guide cooperate to maintain the orientation of the plate as it slides on the front face of the card. The bolt and nut cooperate when loosened to permit the plate to slide on the card and when tightened to clamp the plate and the card together. The front face of the card has a first graduated scale corresponding to the first plurality of equally spaced marked intervals indicating yardage on the front face of a card. The plate has a second graduated scale with spaced intervals equal to the first scale. The plate scale indicates club identifications. The golfer slides the plate on the face of the card to correlate the yardage indications shown on the card to the club selection indications on the plate personally appropriate to the particular golfer. The plate is then clamped in this position. Thus, the scales directly nomographically correlate the determined distance from the golf ball to the pin to the base club selection personally appropriate to the particular golfer using the card.
It is preferred, but not necessary, that the bottom edge of the aperture be straight. If a straight bottom edge is used and the narrow elongated slot is aligned parallel to the bottom edge of the aperture with the scale on the front face of the card aligned with the front face interval markings, the golfer can select the appropriate base club without any need for intermediately observing the determined yardage and then transferring to another scale for appropriate club selection. It is further preferred that a second plate be mounted for sliding juxtaposition on the back face of the card. The nomographic method above described can thus be used to also directly correlate the back face yardages to the personalized club selection for the golfer. The golfer need only determine the length of the pins used at the golf course and position the respective front or back plate accordingly.